DE102017212540A1 - Projection display device with a display in several display levels - Google Patents

Abstract

The invention relates to a projection display device (2) for providing virtual display images on a plurality of mutually offset display planes (E1, E2), comprising:
a projection unit (24) for providing a projection beam;
imaging optics (21) adapted to direct the projection beam onto a combining surface and, depending on the projection beam, to image the virtual display images in the plurality of display planes (E1, E2); wherein the projection unit (24) has a plurality of transparent display elements (26, 27) which are arranged along the beam path of the projection unit (24) at a distance one behind the other.

Description

Technical area

The invention relates to projection display devices, such as head-up displays, for use in motor vehicles or aircraft. Furthermore, the invention relates to projection display devices for displaying images in multiple display levels.

Technical background

Projection display devices are used to project a display image via a HUD disc array on a windshield of a motor vehicle, alternatively via a separate, partially transparent Kombinierfläche positioned between the driver and the windshield to a driver of the motor vehicle information, such as warnings, speed information, vehicle conditions, navigation instructions and the like display. Such projection display devices project an image over the pane so that the driver perceives a virtual display image ahead in the direction of travel. The projected image is located on a display plane whose position and projection distance is determined by the projection display device and the front screen.

Furthermore, projection display devices are known from the prior art, in which virtual display images are displayed on multiple display levels having different distances from the driver.

For example, from the document DE 10 2013 218 108 A1 a head-up display with an image generating device which generates a real image, wherein the light rays of the real image are reflected via at least one mirror to a combiner and thus form a beam path and are reflected from there in the direction of a user, so that the User can perceive a virtual image behind the combiner. At least one mirror has two areas with different curvature fields, the different curvature fields being assigned different areas of the image generation device.

Furthermore, from the document DE 10 2014 226 360 A1 A method for changing an image distance between a virtual image projected by a head-up display and a viewer of the virtual image is known. For this purpose, the head-up display has at least one adjustable scattering surface and a projector with an adjustable objective for projecting an image onto the scattering surface. In addition, it has an adjusting device, which allows the adjustment of the scattering surface and the lens. A scattering surface adjustment signal is output to the adjusting device in order to change the image distance by adjusting the scattering surface. An objective adjustment signal is provided to the adjusting device in order to change the focus and / or the position of the objective as a function of an adjustment of the scattering surface by adjusting the objective so that the objective focuses on the scattering surface.

From the publication DE 10 2014 226 354 A1 For example, a method of changing the image distance between a virtual image of a head-up display and a viewer of the virtual image is known. The head-up display has an image generation unit, a mirror arranged to be movable in at least one direction in the beam path of the light beam for deflecting the light beam and a movement device for moving the mirror. An adjustment signal is output to the moving means for adjusting a distance between the image forming means and the mirror representing the image distance by moving the mirror.

From the publication DE 10 2012 210 445 A1 is a head-up display in a vehicle known. The head-up display has a first image source whose light beams are reflected by a first mirror and a magnifying mirror on a combiner and reflected from there to a user, so that the user the image content of the image source in a first image plane behind the combiner as can perceive a virtual image. A second image source is provided, the light beams of which are also reflected by the magnifying mirror on the combiner and therefrom to the user, the length of the beam path between the second image source and the magnifying mirror being different from the length of the optical path between the first image source and the magnifying mirror so that the user can perceive the image content of the second image source in a second image plane as a virtual image.

From the publication DE 10 2015 205 871 A1 a display device for a field of view display system for use as a head-up display in a motor vehicle is known which comprises a screen arrangement with a plurality of switchable projection screens, which are arranged in a beam path of a projection image to be imaged in each case with a predetermined distance one behind the other, wherein the switchable projection screens between a diffused state and a transparent state are switchable. Using a control unit, the multiple projection screens can be switched at least one of the projection screens is diffused, while the other of the projection screens are switched transparent.

From the publication US Pat. No. 6,720,961 B2 a display device is known, wherein by means of several successively positioned transparent OLED displays, a three-dimensional image of an object is displayed.

From the publication US Pat. No. 6,906,762 B1 a display device is known, wherein a multi-level image is generated by means of a plurality of successively positioned imaging screens.

It is an object of the present invention to provide a projection display device and a projection system with which a representation of a virtual display image in different display planes can be realized in a simple manner.

Disclosure of the invention

This object is achieved by the projection display device for providing virtual display images on a plurality of display levels according to claim 1 and by the projection system according to the independent claim.

Further embodiments are specified in the dependent claims.

• - eine Projektionseinheit zum Bereitstellen eines Projektionsstrahlenbündels; und
• - eine Abbildungsoptik, die ausgebildet ist, um das Projektionsstrahlenbündel auf ein Scheibensegment oder eine Kombinierfläche zu richten und um abhängig von dem Projektionsstrahlenbündel die virtuellen Anzeigebilder in den mehreren Anzeigeebenen abzubilden;

wobei die Projektionseinheit mehrere transparente Anzeigeelemente aufweist, die entlang des Strahlengangs der Projektionseinheit mit Abstand hintereinander angeordnet sind.According to a first aspect, a projection display device is provided for providing virtual display images on a plurality of mutually offset display planes, comprising:

• a projection unit for providing a projection beam; and
• imaging optics configured to direct the projection beam onto a slice segment or combiner surface and to image the virtual display images in the plurality of display planes depending on the projection beam;

wherein the projection unit has a plurality of transparent display elements, which are arranged along the beam path of the projection unit at a distance one behind the other.

One idea of the above projection display device is to generate virtual display images on a plurality of mutually offset display planes by passing a plurality of mutually offset projection images through a common imaging optics. In order to display the display levels to a viewer at different projection distances, a plurality of transparent display elements are positioned offset from one another along the optical axis in the imaging unit. By virtue of the imaging optics, correspondingly offset virtual display planes are generated, which have a distance from one another which results from the spacing of the mutually offset display elements.

According to one embodiment, the projection unit may comprise a plurality of transparent display elements, wherein the pixels of the transparent display elements are self-luminous, wherein in particular at least one of the display elements is designed as a TOLED display element.

According to an alternative embodiment, the projection unit may comprise a plurality of transparent display elements which are arranged in the beam path between a light source and the imaging optics, wherein in particular at least one of the display elements is designed as an LCD display element.

According to an alternative embodiment, the projection unit may comprise a plurality of transparent display elements which are arranged in the beam path between a light source and the imaging optics, wherein in particular at least one of the display elements is designed as an LCD display element and at least one of the display elements is designed as a TOLED display element.

The above projection display device has the advantage that when using LCD displays only one light source for the projection is needed and the additional space is very low, since the display elements between the light source and the imaging optics are arranged. When using LCD displays with a flat bright light source, a high luminance can be achieved. In TOLED displays, the additional space is just as low, because these are planar, light-emitting displays.

Furthermore, the imaging optics can be designed to enlarge the projection image and in particular have a focusing lens or a concave mirror.

According to one embodiment, a light source of the projection unit may be formed flat.

It can be provided that at least one of the display elements is arranged with its surface normal inclined to an optical axis of the projection unit to produce an image in an inclined image plane.

The display elements can each have a planar transparent display device which can be controlled to display a partially transparent colored and / or non-transparent pixel or a transparent pixel.

According to a further aspect, a projection display system with the above projection display device and a control unit is provided, wherein the pixels of the display elements are controllable as transparent, partially transparent in color or non-transparent.

In particular, the control unit can be designed so that the display elements are driven at the same frequency and the individual frequencies are synchronized with each other. This should make it possible to display an image on one of the display elements and to set the others to transparent. Pictures are alternately displayed on the display elements, whereby this is visible through the rest.

Furthermore, this makes it possible to represent non-transparent areas on the display elements.

list of figures

• 1 eine schematische Querschnittsdarstellung eines Projektionsanzeigesystems.

Embodiments are explained below with reference to the accompanying drawings. It shows:

• 1 a schematic cross-sectional view of a projection display system.

Description of embodiments

1 shows a projection display system 1 with a projection display device 2 representing a projection image on a disk segment A a windshield 3 reflected, so a virtual display image for the eye of a user 4 to make visible. The user 4 takes virtual display images B1 . B2 in display levels E1 . E2 true. The virtual display images B1 . B2 in the display levels E1 . E2 be on the user 4 opposite side of the windscreen 3 , ie outside the motor vehicle, perceived.

The projection display device 2 has an imaging optics 21 on, in the illustrated embodiment, a concave mirror 22 and a flat mirror 23 as optical imaging elements. Other embodiments may include other optical imaging elements, such as a condenser lens, a convex lens, and the like. In the illustrated embodiment, one of a projection unit 24 emitted projection image on the flat mirror 23 on the concave mirror 22 reflected and there on a disk segment A , which serves as a combiner, reflects around the corresponding virtual display images B1 . B2 for the user's eye 4 provide.

The projection unit 24 has a light source 25 and a first display element 26 and a second display element 27 on. The display elements may be formed, for example, as LCD display elements. The display elements 26 . 27 are provided with controllable pixels to represent a projection image.

The LCD display elements 26 . 27 are substantially transparent and can each generate a partially transparent or non-transparent pixel by driving. The display elements 26 . 27 each have a planar transparent LCD display device that is controllable to represent a colored and / or opaque pixel or a transparent pixel.

The light source 25 is preferably flat, to a flat backlight of the display elements 26 . 27 provide, so that depending on the driving of the pixels of the display elements 26 . 27 a corresponding projection image in the direction of the flat mirror 23 is projected.

In an alternative embodiment, the transparent display elements may be formed with self-luminous controllable pixels, such. B. as TOLED display elements. In this case, can be dispensed with a separate light source.

In an alternative embodiment, the transparent display elements may be formed from a combination of transparent LCD display elements and self-illuminating controllable pixels, such. B. as TOLED display elements.

Through the imaging optics 21 become pixels on the various display elements 26 . 27 in the different virtual display levels E1 . E2 shown. The distance between the virtual display levels E1 . E2 depends essentially on the distance of the display elements 26 . 27 and the imaging properties or the magnification properties of the imaging optics 21 from.

Furthermore, the distance of the virtual image planes, which corresponds to a perceived distance between display images, can be determined by a focus change element 29 between the first and second display elements 26 . 27 to be changed.

Such an optical focus change element can be made of a transparent Dispersion material such as glass, PMMA or the like may be formed. The display elements can furthermore be designed in the form of a multilayer display with mutually parallel image representation planes or image representation planes arranged inclined to one another. The fact that the structure described above requires only one light source, the cost and space of such a projection display arrangement can remain low. Even when using self-luminous transparent display elements, such. As TOLEDs, the cost and space of the projection display arrangement remain low.

The projection display system 1 can be a control unit 10 exhibit. At least one pixel of the first display element 26 and a pixel of the second display element 27 are in the beam path of the projection unit 24 arranged one behind the other. The control unit 10 controls the display elements 26 . 27 so that at least one of the pixels can be switched transparent.

Alternatively, the control unit 10 Control signals to the display elements 26 . 27 give and control the pixels of the display elements as transparent, partially transparent colored or non-transparent. In particular, the control unit is designed so that the display elements are driven at the same frequency and the individual frequencies are synchronized with each other.

LIST OF REFERENCE NUMBERS

1

Projection display system

2

Projection display device

3

windscreen

4

user

B1, B2

virtual display images

E1, E2

display levels

21

imaging optics

22

concave mirror

23

flat mirrors

24

projection unit

25

light source

26

first display element

27

second display element

29

Focus change element

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102013218108 A1 [0004]
• DE 102014226360 A1 [0005]
• DE 102014226354 A1 [0006]
• DE 102012210445 A1 [0007]
• DE 102015205871 A1 [0008]
• US 6720961 B2 [0009]
• US 6906762 B1 [0010]

Claims (9)

A projection display device (2) for providing virtual display images on a plurality of mutually offset display planes (E1, E2), comprising: - a projection unit (24) for providing a projection beam; imaging optics (21) adapted to direct the projection beam onto a combining surface and, depending on the projection beam, to image the virtual display images in the plurality of display planes (E1, E2); characterized in that the projection unit (24) comprises a plurality of transparent display elements (26, 27) which are arranged along the beam path of the projection unit (24) at a distance one behind the other. Projection display device (2) according to Claim 1 wherein the projection unit comprises a plurality of transparent display elements (26, 27), wherein the pixels of the transparent display elements (26, 27) are self-luminous, wherein in particular at least one of the display elements (26, 27) is designed as a TOLED display element. Projection display device (2) according to Claim 1 wherein the projection unit comprises a plurality of transparent display elements (26, 27) which are arranged in the beam path between a light source (25) and the imaging optics (21), wherein in particular at least one of the display elements (26, 27) is formed as an LCD display element , Projection display device (2) according to Claim 1 wherein the projection unit (24) comprises a plurality of transparent display elements (26, 27) which are arranged in the beam path between a light source (25) and the imaging optics (21), wherein in particular at least one of the display elements (26) as LCD display element and at least one of the display elements (27) is designed as a TOLED display element Projection display device (2) according to Claim 3 or 4 wherein the light source (25) of the projection unit (24) is formed flat. Projection display device (2) according to one of Claims 1 to 5 wherein the imaging optics (21) is designed to enlarge the projection image and in particular a focusing lens or a concave mirror (22). Projection display device (2) according to one of Claims 1 to 6 wherein at least one of the display elements (26, 27) is arranged with its surface normal inclined to an optical axis of the projection unit (21) to produce an image in an inclined image plane. Projection display device (2) according to one of Claims 1 to 7 , wherein the display elements (26, 27) are each controllable to represent partially transparent colored and / or non-transparent pixels or transparent pixels. Projection display system (1) with a projection display device (2) according to Claim 8 and a control unit, wherein the pixels of the display elements (26, 27) as a transparent, partially transparent color or intransparent are controlled.

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